Patent GB-454190-A (GB)
Title: Improvements in or relating to the manufacture of artificial sponges
IPC: B29C44/00
Filed: 1935-11-06
Abstract: For manufacturing artificial sponges, a pasty mass having a basis of viscose, fibres and soluble crystals is moulded under considerable pressure, for example, discontinuously by pressing blocks by the casting process or continuously by extrusion, thereby producing an orientated structure, the blocks or bars are divided across the grain of orientation into sections which are subjected to pronounced deformation by pressure in the same general direction as the grain of orientation so as to disorientate the structures, the blocks or bars are divided across which are equally strong in all directions.  The deforming pressure may be applied by plates with plane or curved pressure surfaces, e.g. to produce an egg-shaped body.  Preferably, a continuous moulding process is employed, using an appropriate type of screw, or piston extrusion press.  The pressure should be of the order of 80--100 kgms./sq. cm. and the extruded bar may be constricted by means of a nose, 2--10 cms. in length and with an aperture of 10--60 DEG  placed in front of the nozzle.  The constriction may be 5--25 per cent.  In an example 20 parts of hemp are malaxated with 400 parts of viscose containing 10 per cent of cellulose and 1200 parts of sodium sulphate crystals.  The mass is extruded in an apparatus, e.g. of the "cake-press" type through a nozzle 150 mms. in diameter in front of which is disposed a short conical nose which reduces the diameter of the bar to 125 mms.  The bar is cut into portions which are compressed in the longitudinal direction between two mould members mounted on the plate of a press and then coagulated.  To facilitate removal from the mould, the portions may be enveloped in a piece of cloth. The mould may be spherical or ovoid for example.  Polyhedric bodies may be encrusted in the small blocks during deformation.ALSO:For manufacturing artificial sponges, a pasty mass having a basis of viscose, fibres and soluble crystals is moulded under considerable pressure, for example, discontinuously by pressing blocks by the casting process or continuously by extrusion, thereby producing an orientated structure, the blocks or bars are divided across the grain of orientation into sections which are subjected to pronounced deformation by pressure in the same general direction as the grain of orientation so as to disorientate the structures and produce after coagulation sponges which are equally strong in all directions.  The deforming pressure may be applied by plates with plane or curved pressure surfaces, e.g. to produce an egg-shaped body.  Preferably, a continuous moulding process is employed, using an appropriate type of screw, or piston extrusion press.  The pressure should be of the order of 80-100 kgms./sq. cm. and the extruded bar may be constricted by means of a nose, 2-10 cms. in length and with an aperture of 10-60 DEG  placed in front of the nozzle.  The constriction may be 5-25 per cent.  In an example, 20 parts of hemp are malaxated with 400 parts of viscose containing 10 per cent of cellulose and 1200 parts of sodium sulphate crystals.  The mass is extruded in an apparatus, e.g. of the "cake-press" type through a nozzle 15 mms. in diameter in front of which is disposed a short conical nose which reduces the diameter of the bar to 125 mms.  The bar is cut into portions which are compressed in the longitudinal direction between two mould members mounted on the plates of a press and then coagulated.  To facilitate removal from the mould, the portions may be enveloped in a piece of cloth.  The mould may be spherical or ovoid for example.  Polyhedric bodies may be encrusted in the small blocks during deformation.